Process and apparatus for separating gasoline from crude oil



April 17, 1928. l 1,666,300.

A. E. PEw, JR., ET AL PROCESS AND APPARATUS FOR SEPARATING GASOLINE `FROM CRUDE OIL y /fw/fA/raes h//T/VESS: v r/ur f. an?

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2 Smeets-Sheen- 2 A. E. PEW, JR., ET AL PROCESS AND APPARATUS FOR SEPARATING GASOLINE FROM CRUDE OIL Filed Feb. 25. 1924 April 17, 1928.

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UNITEDSTATES PATENT oFF ics.`

ARTIUR E. PEW, JR., OF BRYN MAWR, AND HENRY THOMAS, OF RIDLEY PARK, PENN- SYLVAN IA, ASSIGNORS TO SUN OIL COMPANY, OF PHILADELPHIA, PENNSYLVANIA,

A CORPORATION OF NEW JERSEY.`

PROCESS AND APPARATUS FOR SEPARATING GASOLINE FROM 'CRUDE OII.

Application led February 23, 1924.

The obje-ct of the invention is to effect a practically quantitative separation of gasoline from crude oil.

The invention comprises a process adapted to'eil'ect such result and also an apparatus adapted to execute the process with a high degree of efficiency and economy.

In the drawings:

Fig. l is a diagram of the entire apparatus.

Figs. 2, 3 and 4 are detail views of a vaporizing fractional distilling unit of the plant; Fig. 2 being a horizontal section through the unit on line 22 Fig. 3; and Figs. 3 and 4 vertical sections taken at right angles to each other, on the lines 3--3 and 4-4.respectively of Fig. 2.

Preparatory to a detailed description of the entire apparatus, the operation will be described in a very general way, reference being had to Fig. l.

Criide oil is pumped through pump a and line bi, thence through reflux condenser cl of fractional separating tower c, thence through line e and reflux condenser g of fractional separating tower f, and thence through line h to the vaporizing fractional distilling unit z'. The light distillate fractions herein evaporated ar'e taken off at j, j, etc. and pass, wholly or partly, through line c to a condenser m, or wholly or partly through line 'n to tower c. The residual oil fromthis distillation in z' flows through pipe o into the still 1', first spreading over the pans p, on which occurs vaporization of the remaining and heavier gasoline fractions. Distillate from the still 7 passes by line s to the tower f, wherein the heavier gasoline fractions are vaporized and pass to the condenser t, the residual liquid (gas oil) going to storage. The residual oil from the still r4 is pumped, by pump u through line t', to the unit z', where its heat is utilized to effect distillation of' the lighter gasoline. Deprived largely of its heat, it then flows through line w to storage, where it is utilized as fuel oil, or'subjected to further distillation. The lighty distillate enteringtower c from line n is therein fractionated, the vapors passing to a condenser a: and the oo ndensate flowing through line y to the st1ll (as shown, through line o). I

The towers c and f may represent any suitable fractional separator. We prefer to con- Serial No. 694,471.

tion filed of even date herewith, Serial No.

694,475, and they need'not be further described herein.

The preferred specific construction of the vaporizing fractional distilling apparatus z' is shown in Figs. 2, 3 and 4.

At opposite sides of the casing of this apparatus i are tiers of headers ll. Connecting opposite headers 11 are tubes 12, which extend through the open interior of the apparatus. Fuel oil from the still r and pipe v enters the lowest header 11 at one side and thence flows through the lower-set of tubes 12 to the lowest header 11 on the opposite side. By means of a curved tube 13, the oil flows into a lheader 11 of the second tier and takes the same course through the second tier of tubes that it took through the first, only in the opposite direction. The oil thus flows successively through all the tiers of headers and tubes, finally discharg-V ing into the pipe lw.

The crude oil entering the top of this apparatus has been-raised in temperature, by passage through the reflux condensers d and g of towers c and f, and may have any desired temperature, say 190 F. This oil drops on the horizontal tubes 12 and forms a film thereon and drips therefrom onto tubes below. As the oil drips down it contacts with pipes of progressively increasing temperature. The oil pumped from the still toward the lower tier of tubes may have a temperature of (say) 520 F. and the downdripping oil will finally contact with tubes raised to a temperature approximating the still temperature. There is, therefore, an exchange of heat between the fuel oil flowing through the ltubes andthe down-dripping crude oil, so that the fuel oil leaving at the top through line w will have a ltemperature* nolt much above that of the entering crude o1 a l v i Y -In this apparatus, there is a distillation of progressively heavierV fractions of gasoline. The vapors may be taken off at as many difloe ferent levels as desired and may be separately condensed; but this is ordinarily undesirable, and we have, therefore', shown leads to a common pipe lc leading to a condenser m. Alternatively, the vapors may be led through pipe n to tower c, which is heated only by the heat of the incoming vapors and in which there is some fractionation, the vapors passing to condenser m and the condensate flowing, together with the unvaporized oil dripping oil the lowest tubes 12, into the still.

llt will be understood that, preferably, the separation of only lthe lighter gasoline is contemplated in the multiple-tube distiller i and the tower c, the oil flowing through pipe o containing heavier' gasoline fractions. rlhese fractions will all evaporate on the pans p and will not enter the body of oilk in the still at all it' the still is maintained at a proper temperature, say 520 F. The distillate from the still enters tower f and is there "fractionated, the vapors comprising all the heavier fractions of gasoline, passing to the condenser t.

While we have described the apparatus and process as adapted to the separation of gasoline from crude oil, it will be understood that they are also applicable, under different conditions of heat, to the separation of light cuts from any petroleum distillate. lNhere, therefore, in the claims, reference is made to the separation of asolme from crude oil, it is intended to inc ude, as anv equivalent, the separation of any lighter traction or fractionsof mineral oil froma heavier' fraction or fractions thereof, such as a petroleum distillate. c

No special meansy need be adapted to regulate the pressure throughout the system, but it desired any predetermined absolute pressure may be obtained, by known means, from superatniosphericgree of vacuum. he system is especially adapted to vacuum distillation, and it is preferable to use a high degree of vacuum, varying from an ,absolute pressure not exceeding twenty-live millimeters mercury down to as near zero pressure as is practicable.

Having now fully described our invention, what we claim and desire to protect by Letters Patent is: i

l. rThe process of vaporizing mineral oil which comprises heating mineral oil to a distilling temperature and iowing a stream of said hot oil within a lstill at successively higher elevations and dividing the hot o1l flowing at each elevationvv into confined, multiple, spaced a art streams, flowing mineral y oil to be vaporlzed into the upper part ofthe still and so disseminating it that it passes intoheat exchange relation, but out of contact, with said first mentioned hot oil streams and distributes itself in thin films in heat exchange relation with successively lower oil fessure to yajhigh de-` aeeaeoe streams and with progressively hotter multiple oil streams at successively lower elevations so as to produce an intensive heating action and progressiveiractional vaporization as well as the substantially complete'vapoi-ization of fractions having boiling points below the progressively rising temperatures to which the. downflowing distributed and disseminated oil is subjected.

QQA fractional distilling apparatus ofthe character described comprising a casing, a multiplicity of tubes extending laterally throughthe casing, a residual oil still separelation with said vapor outlet of the trac-l tionating tower, and means adapted to convey residualoil from the casing to the still.

3. A fractional distilling apparatus ot' the character described comprising a casing, a multiplicity ot tubes extending laterally through the casing, aresidual oil still in which relatively high boiling point fractions ofthe oil are adapted to be vaporized, means adapted to convey residual oil trom said still and distribute the oil to said tubes, said casing having a vapor outlet, a fractional separating towel' having a vapor outlet, means adapted to convey vapor from the vapor outlet from the casing to the fractional separating tower. means adapted to convey a stream ot' oil to the upprr part of said casing, said last named oil conveying means heilig in heat exchange relation with the vapor outlet from said fractional separating tower, and means to convey residual oil from'the casing and from the fractional separating tower to the still. l i

fl. A' Jfractional distilling apparatus of the character described comprising a casing, a multiplicity `of tubes extending laterally through the casing. a residual oil still in which relatively high boiling point fractions `of the oil 'are adapted to be vaporized, said still having a vapor outlet, a ractionating tower communicating with the vapor outlet from said 'still and having a vapor outlet, means adapted to convey a stream of residual oil from said still and distribute the oil to said tubes, a vapor outlet from the casing, a

fractional separating tower having a vapor outlet and connected with the vapor outlet from the casmg, means to convey a stream of oil to the upper part of said casing, said -last named oil-conveying means being in heat-exchange relation with the vapor outlet lli titi

from said fractionating tower and said vapor outlet from said fractional separating tower, and means to convey residual oil from the casing to\the still.

5. The process of vaporizing mineral oil which comprises heating mineral oil to a distilling temperature and fiowing a stream of said hot oil within a still at successively higher elevations and dividing the hot oil flowing at such elevation into confined. multiple, spaced apart streams, flowing mineral oil to be vaporizcd into the upper part of the still and so disseminating it that it passes into heat exchange relation, but out of contact, with said first mentioned hot oil streams and distributesv itself in thin films in heat exchange relation with successively lower oil streams and with progressively hotter multiple oil streams at successively lower elevations so as to produce an intensive heating action and progressive fractional vaporization as well as the substantially complete vaporization of fractions having boiling points below the progressively rising temperatures to which the downflowing distributed and disseminated oil is subjected, removing the vapors. effecting vaporization in another still of still higher boiling fractions, and utilizing the residue of the last vaporization to afford a continuous supply of oil for circulation through the first still at the specified successively higher elevations. L

6. The `process as set Aforth invclaim l wherein the vaporizing space within thestill .is maintained under a vacuum.

. over said confined paths and thereby absorb `heat from the firstv mentioned hotter oil without direct contact therewith and be thereby partly' vaporized, then heating the residue toa higher Vtemperature to effect vaporizaton of higher boiling fractions, utilizlng the lresidue of the last vaporizaton to afford a-continued supply of oil for circulation back and forth as specified, fractionating the vapors ofthe last vaporization, and

utilizing the vapors from the last fra-ctionation to preheat the second named stream of mineral oil in its flow toward said confined space.

8. The process of separating gasoline from crude mineral oil which comprises circulating highly heated mineral oil in circuitous and confined paths back and forth at progressively higher levels within a confined space, flowing another stream of mineral oil to be vaporized at a substantially lower temperature toward and into said confined space and allowing it todescend by gravity within saidspace and spread outover said confined paths and thereby absorb heat from the first mentioned hotter oil Without direct contact therewith and be thereby partly lvaporized, then heating the residue to a higher temperature to effect further partial vaporization, utilizing the residue of the last vaporization to afford a continued supply of o1l for circulation back and forth as specified, fractionating vapors of the first vaporization specified, and utilizing the vapors from such fractionation/t0' preheat the oil in the second named stream of mineral oil as it flows toward said confined space.

9. The process of separating gasoline from crude mineral oil which comprises circulating highly heated mineralr oil in circuitous'and confined paths back and forth at progressively higher levels within a confined space, flowing another stream of mineral oil to be vaporized at a substantially lower temperature .toward and into said confined space and allowing it to descend by gravity within said space and spread out over said confined paths and thereby absorb heat from the first mentioned hotter oil Without direct Contact therewith and be thereby partly vaporized,

'then heating the residue to a higher temperature to effect-further partial vaporization7 utilizing the residue of the last vaporization to afford a continued supply of oil for circulation back and forth as specified, fractionating the vapors of the first vaporization, and returning the residual oil from such fractionation to the residue above specified that is being subjected to further partial vaporization.

In testimony of which invention, we have hereunto set our hands, at Philadelphia, Pa., on this 14th day of February, 1924.

ARTHUR E. PEW, JR. HENRY' THOMAS. 

